Variable eccentric and locating plate

ABSTRACT

A tufting machine in which a double eccentric is utilized to vary the stroke of the needle bar and in which an adjusting device is associated with the connecting rod and is manipulatable to maintain the bottom dead center position of the needle bar regardless of variation in stroke.

United States Patent 1191 Higgins Dec. 31, 1974 [5 VARIABLE ECCENTRIC AND LOCATING 2,961,982 11/1960 Wear 112/79 R PLATE 3,653,346 4/1972 Parsons 112/79 R [75] Inventor: John Higgins, Goose Green, FOREIGN PATENTS OR APPLICATIONS England 685,936 12/1939 Germany 112/221 [7.3] Assigneez The singer Company New York 872,724 4/1953 Germany 112/221 Primary Examiner-Werner H. Schroeder [22] Filed: Feb. 14, 1974 Attorney, Agent, or Firm-Robert E. Smith; Edward L. [2]] App] No: 439 481 Bell; Alan Ruderman 57] ABSTRACT 52 US. l. i511 Int 5 112/79 74/371 i A tufting'machine 1n whlch adouble eccentrlc s un- 58] Fie'ld A 266 220 lized to vary the stroke of the needle bar and in which 112/22l 74/571 an adjusting device is associated with the connectingrod and is manipulatable to maintain the bottom dead References Cited center position of the needle bar regardless of varia-- tion in stroke. UNITED STATES PATENTS 2,592,237 4/1952 Bradley 74/571 M 6 Clams 6 Draw PATENTEDDEE31 I974 sum 1 or A Wm m MWY PATENTEU I974 3. 857. 345

sum 30F 4 FIGS BACKGROUND OF THE INVENTION The present invention relates to tufting machines capable of producing articles such as pile carpets. It is standard-on such machines to incorporate the capability of varying needle bar stroke in order to effect a variation in pile depth as may be desired. It has also been conventional to utilize a double eccentric mechanism to effectuate such stroke variation. The use of double eccentric mechanisms to regulate the stroke of a reciprocable member, such as a knitting needle, has been known heretofore. For example, U.S. Pat. No. 2,459,587 issued Jan. 18, 1949 discloses the use of such a double eccentric mechanism to vary the stroke of a knitting needle employed in the mending of hosiery. U.S. Pat. No. 2,477,587 issued Aug. 2, I949 illustrates the use of a double eccentric mechanism to provide for variation in the stroke of a punch press. In the tufting art, however, it has heretofore been necessary to make relatively complicated and time consuming adjustments including in some cases adjustments in the bed plate and looper bar mechanism to accomodate changes in needle bar stroke. Any such changes in looper bar mechanism setting, usually also occasioning a change in timing, were extremely time consuming and necessarily resulted in substantial down or inoperative time for the machine.

SUMMARY OF THE INVENTION It is one object of the present invention to provide a tufting machine in which needle bar stroke can be var-v ied without necessitating readjustment of the looper bar mechanism. It is another object of this invention to provide a tufting machine in which needle bar stroke can be varied without the need for a time-consuming readjustment in the timing of the machine.

It is still another object of this invention to provide a tufting machine in which the needle bar stroke can be readily altered and the bottom dead center position of the needle bar can be maintained at any predetermined position.

Other objects and advantages of the invention will become readily apparent from the following description of the invention.

According to the present invention there is provided in a tufting machine having a drive shaft, a connecting rod operably connected thereto for reciprocating movement, a needle bar drivable reciprocably by said connecting rod, and double eccentric means for regulating the stroke of said needle bar, the improvement comprising a first eccentric rotatable on said drive shaft into any one of a plurality of preselected positions and a second eccentric carried by said first eccentric and rotatable into any one ofa plurality of preselected positions relative to said first eccentric to thereby establish the desired stroke for said needle bar, means for locking said first and second eccentrics in fixed relation to each other and in preselected position relative to said drive shaft, and adjusting means associated with said connecting rod for maintaining the bottom dead center position of said needle bar at a predetermined position regardless of the variation in stroke effected for said needle bar.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully comprehended it will now be described, by way of example,

with reference to the accompanying drawings in which:

FIG. 1 is a side elevation of a variable eccentric assembly and an adjusting device in sectional view;

FIG. 2 is an end elevation in the direction of the DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings a'tufting machine indicated generally by the reference numeral 100 has a variable eccentric assembly 101 for imparting an adjustable stroke to a needle bar 102 of the tufting machine. The eccentric assembly includes a locating flange 104 keyed to a drive shaft 106 of the tufting machine, a first or inner eccentric 108 journa'lled on the shaft and rotatable into any one of a plurality of preselected positions, and a second or outer eccentric 110 journalled on the inner eccentric 108 and rotatable into any one of a plurality of preselected positions relative to the first eccentric. As shown, outer eccentric 110 has a se-v curing flange 112 abutting the locating flange 104.

However, as will be readily appreciated it is possible to provide the securing flange on either of the eccentrics. Numbered locating marks and a reference mark are provided on the circumferential faces of said locating and securing flanges, respectively, so that the relative positions of the outer eccentric and the. shaft may be noted. I

When the outer eccentric is rotated into any one of the preselected positions on the shaft, as shown by the required locating mark being in register with the reference mark, a screw 114 is passed through a plain bore 116 on the locating flange 104 to connect with a threaded bore 118 in the securing flange 112, thus locking the outer eccentric relative to the shaft. A plurality of such plain bores 116 and threaded bores 118 are provided on the locating and the securing flanges respectively but only one pair of these bores are in register in each preselected position.

The inner and the outer eccentrics 108 and 110 are provided with annular flanges 120 and 122 respectively at the ends thereof remote from the locating plate 104. The circumferential face of the flange 120 is provided with numbered locating marks, corresponding to the marks on the locating flange 104 and the flange 122 is provided with a reference mark so that the relative positions of the eccentrics and thus the stroke of the needle bar may be noted. In any preselected relative position of the eccentrics a screw 124 is passed through a plain bore 126 on the flange 120 into a registering threaded bore 128 in the flange 122 and thus the flanges are connected together.

One end 130, i.e., the big end, of a connecting rod 132 is rotatably mounted on bearings 134 on the outer eccentric, the other end 136 i.e., the small end of the connecting rod, being pivotably connected with the needle bar 102 by way of an adjusting device 138 for adjusting the bottom dead centre position of the needle bar to any desired position. This device is thus used to ensure that for all lengths of stroke the bottom dead centre position of the needle may be maintained constant.

The adjusting device 138 comprises a clevis 140 attached to the needle bar 102 by means of a push rod 142. The clevis has in each of its opposed parallel limbs a vertical slot to accommodate a pivot bolt 144 passing therethrough. The small end of the connecting rod pivots on bearings 146 about the bolt 144, and nuts 148 are provided to prevent the bolt from moving in an axial direction.

To locate the bolt 144 accurately in the slots, locating plates 150 are provided on either side of the clevis, the bolt 144 passing through a close fitting aperture in each of the plates. The plates 150 are each provided with a corresponding arrangement of grooves 152 running both horizontally and vertically across two opposite end faces thereof, the plates being reversible. Each pair of corresponding selected grooves on the plates 150 is dimensioned to receive a horizontal raised rib 154 provided on each of the outer faces of the parallel limbs of the clevis. In this manner the pivot bolt 144 can be moved further from or closer to the needle bar 102, thus adjusting the bottom dead centre position of the needle bar. The grooves are each marked with an identifying number so that the correct groove may be selected for a given length of stroke to maintain constant the bottom dead centre position of the needle bar.

To adjust the length of stroke, the machine is stopped with the needles at the bottom of the stroke and the screws 114 and 124 are removed. A tommy bar (not shown) is placed into one of a plurality of holes 156 located around the circumferential face of the flange of the outer eccentric, and the inner and/or the outer eccentric is rotated until the required locating mark, indicating the length of stroke on said flange 120, is aligned with the reference mark on the flange 122.'The eccentrics 103 and 110 are secured together by means of the screw 124.

The inner and the outer eccentrics are rotated together until the locating mark on the locating flange 104 corresponding to said locating mark on the inner eccentric is aligned with the reference mark on the securing flange 112. This ensures that there is no change in timing of the needle bar with respect to the shaft. The securing flange 112 is then locked to the locating flange 104 by means of the screw 114.

To adjust the bottom dead centre position of the needle bar to maintain it at a constant location, the bolt 144 is loosened or removed and the selected pair of corresponding grooves are each positioned to receive the respective rib. Preferably to simplify the selection of the grooves, the groove identifying numbers on the locating plates 150 are chosen such that if the bottom dead centre position was previously correct, then it will be sufficient to maintain the same difference between the groove number and the stroke length locating mark number as was previously present. To alter the bottom dead centre position in the embodiment shown in the drawings setting the groove number to a lower number, e.g., 5. to 4 will lower the position by l/32 inch, 5 to 3 will lower by l/l6 inch and vice versa.

Preferably, also for the sake of simplicity, the locating plates 150 have a maximum of two horizontal and two vertical grooves per face and the groove numbers are located at the edge nearest the clevis, the lowest number referring to the bottom groove.

When adjusting the stroke of the needle bar of the tufting machine, the stroke of the individual push rods 142 should be adjusted one eccentric assembly and set of locating plates at a time, in order to assist in maintenance of needle pick up position.

When adjusting the pick up position, it may be possible to make a small adjustment by releasing several sets of locating plates 150 and using needle bar deflection to enable the new pick up location to be set. Alternatively, the needle bar may be supported by chocks while all locating plates 150 are released and re-set.

It will be understood that various changes in the details materials, arrangements of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principles and scope of the invention.

Having thus set forth the nature of the invention, what 1 claim herein is:

1. in a tufting machine having a drive shaft, a connecting rod operably connected thereto for reciprocat ing movement, a needle bar drivable reciprocably by said connecting rod,'and double eccentric means for regulating the stroke of said needle bar, the improvement comprising a first eccentric rotatable on said drive shaft into any one of a plurality of preselected positions and a second eccentric carried by said first eccentric and rotatable into any one of a plurality of preselected positions relative to said first eccentric to thereby establish the desired stroke for said needle bar,

means for locking said first and second eccentrics infixed relation to each other and in preselected position relative to said drive shaft, and adjusting means associated with said connecting rod for maintaining the bottom dead centre position of said needle bar at a predetermined position regardless of the variation in stroke effected for said needle bar.

2. 'A tufting machine according to claim 1, wherein said adjusting means comprises a clevis having in each of its opposed parallel limbs a slot aligned with the longitudinal axis of the respective limb, the outermost face of each of said limbs being provided with a rasiedrib extending perpendicularly to the longitudinal axis of the respective limb, a pair of removable locating plates being provided for positioning on the respective outermost faces of the clevis, each of said plates having an arrangement of grooves therein dimensionedfor selective reception of the respective rib and each having an aperture therethrough, a pivot bolt extending between the plates through said slots in the clevis, said bolt being operatively connected to one of said connecting rod and needle bar, and the clevis being thus fixedly secured to one of said needle bar and connecting rod.

3. A tufting machine according to claim 1, wherein a radially projecting annular locating flange is keyed to said drive shaft, one of said eccentrics has a radially projecting annular flange and the other of said eccentrics has two radially projecting annular flanges, one of said flanges on said other eccentric abuts the said locating flange, the second of the flanges on said other eccentric abuts the flange on said one eccentric, locating and reference marks being provided on the circumferential faces of said flanges to indicate the preselected position of said other eccentric relative to said drive gether by means of a threaded member engageable in said registering bores.

5. A tufting machine according to claims 2 and 3, wherein the grooves on the said locating plates have identifying marks bearing a relationship with the marks on the eccentric assembly.

6. A tufting machine according to claim 3, wherein said one eccentric is said first eccentric and said other eccentric is said second eccentric. 

1. In a tufting machine having a drive shaft, a connecting rod operably connected thereto for reciprocating movement, a needle bar drivable reciprocably by said connecting rod, and double eccentric means for regulating the stroke of said needle bar, the improvement comprising a first eccentric rotatable on said drive shaft into any one of a plurality of preselected positions and a second eccentric carried by said first eccentric and rotatable into any one of a plurality of preselected positions relative to said first eccentric to thereby establish the desired stroke for said needle bar, means for locking said first and second eccentrics in fixed relation to each other and in preselected position relative to said drive shaft, and adjusting means associated with said connecting rod for maintaining the bottom dead centre position of said needle bar at a predetermined position regardless of the variation in stroke effected for said needle bar.
 2. A tufting machine according to claim 1, wherein said adjusting means comprises a clevis having in each of its opposed parallel limbs a slot aligned with the longitudinal axis of the respective limb, the outermost face of each of said limbs being provided with a rasied rib extending perpendicularly to the longitudinal axis of the respective limb, a pair of removable locating plates being provided for positioning on the respective outermost faces of the clevis, each of said plates having an arrangement of grooves therein dimensioned for selective reception of the respective rib and each having an aperture therethrough, a pivot bolt extending between the plates through said slots in the clevis, said bolt being operatively connected to one of said connecting rod and needle bar, and the clevis being thus fixedly secured to one of said needle bar and connecting rod.
 3. A tufting machine according to claim 1, wherein a radially projecting annular locating flange is keyed to said drive shaft, one of said eccentrics has a radially projecting annular flange and the other of said eccentrics has two radially projecting annular flanges, one of said flanges on said other eccentric abuts the said locating flange, the second of the flanges on said other eccentric abuts the flange on said one eccentric, locating and reference marks being provided on the circumferential faces of said flanges to indicate the preselected position of said other eccentric relative to said drive shaft and the position of said other eccentric relative to said one eccentric.
 4. A tufting machine according to claim 3, wherein one flange of each pair of abutting flanges is provided with a plurality of threaded bores and the other flange of each pair of abutting flanges is provided with a plurality of plain bores, the bores being arranged such that for each pair of abutting flanges one plain bore will be in register with one threaded bore in each preselected position, the pair of flanges then being lockable together by means of a threaded member engageable in said registering bores.
 5. A tufting machine according to claims 2 and 3, wherein the grooves on the said locating plates have identifying marks bearing a relationship with the marks on the eccentric assembly.
 6. A tufting machine according to claim 3, wherein said one eccentric is said first eccentric and said other eccentric is said second eccentric. 